1. Field of the Invention
The field of the invention relates to electronic locks generally, and more particularly to certain new and useful advances yielding improved actuation and tamper-resistance of an electronic lock, of which the following is a specification, reference being had to the drawings accompanying and forming a part of the same.
2. Discussion of Related Art
Conventional mechanical locks include the basic components of a body, a rotatable cylinder positioned within the body and a series of tumblers. When locked, the tumblers extend from the rotatable cylinder into the body to prevent rotation of the cylinder relative to the body. A specifically shaped key inserted in a keyhole within the cylinder engages the tumblers and moves them such that the cylinder is free to rotate relative to the body, thus unlocking the lock.
Electronic locks provide additional security features, but their relatively small size limits the size and number of internal components that can be housed therein. Although a solenoid is incorporated within a rotatable cylinder of an electronic lock, the solenoid's power source is typically incorporated within a key of the electronic lock. The power source delivers electrical power to the solenoid when the key engages the rotatable cylinder and microprocessor in the rotatable cylinder determines that a code stored in a memory of the key authorizes access.
To resist tampering by sharp blows, some electronic locks incorporate a spring-biased tamper element into the rotatable cylinder. When a sharp blow to the face of the electronic lock moves the solenoid plunger from its locking position, the sharp blow simultaneously moves the spring-based tamper element to interferingly engage the one or more tumblers.
To resist tampering by an external magnetic field, some electronic locks at least partially enclose the solenoid plunger with a ferromagnetic material. When a strong external magnetic field is applied to the electronic lock, the ferromagnetic enclosure causes the solenoid plunger to move out of the ferromagnetic enclosure and block the movement of one or more tumblers, which movement would otherwise unlock the electronic lock.
Notwithstanding the features of electronic locks referenced above, it would be advantageous to develop an electronic lock that has at least one of improved power consumption, improved attack resistance, and improved environmental robustness.